1. 6-3B Regular Polyhedrons
What is a regular polyhedron?
What are Platonic solids?
What are the names of the Platonic solids?

2. Regular Polyhedron Congruent edges and faces
Faces that are regular polygons
An equal number of edges meeting at each vertex
A convex regular polyhedron is one with no “dents”.

3. Platonic Solids
Platonic Solids are five convex regular polyhedrons discovered over 2,000 years ago and named in honor of the Greek philosopher Plato. They are:
Regular tetrahedron
Regular hexahedron
Regular octahedron
Regular dodecahedron
Regular icosahedron

4. Regular tetrahedron

5. Regular hexahedron

6. Regular octahedron

7. Regular dodecahedron

8. Regular icosahedron

9. Purely Platonic Name Type of face # of faces # of edges # of vertices
Tetrahedron
Triangle 4 6
Hexahedron
Square 6 12 8
Octahedron
Triangle 8 12 6
Dodecahedron
Pentagon 12 20 30
Icosahedron
Triangle 20 12 30

10. Name the convex regular polyhedron that has the given set of characteristics
Five equilateral triangular faces meet at each vertex
Square faces
Three equilateral triangular faces meet at each vertex
Regular icosahedron
Regular hexahedron
Regular tetrahedron

11. Do platonic solids occur in nature?
Chrome alum octahedrons
Salt hexahedrons
Sugar

12. Concave regular polyhedrons
Great Icosahedron
Great Stellated Dodecahedron
Small Stellated Dodecahedron

13. Uniform Polyhedra

14. What is a regular polyhedron?
Congruent edges and faces, faces that are regular polygons, and an equal number of edges meeting at each vertex.
What are Platonic solids?
Platonic Solids are five convex regular polyhedrons.
What are the names of the Platonic solids?
Tetrahedron, hexahedron, octahedron, dodecahedron, icosahedron.

15. Assignment 6-3B
Page 450,
1-10,23-24